Glad you enjoyed it.

>2. What Z characteristics did you build your common mode transformer to? These are designed for a 50 ohm system. This video shows some of the measurements I had made with this core and how it compares. If someone shows me a black toroid with some coax, it has no value. I can use Google images if that's all I am after. I want the material selection. The rest, I can figure out. A good reference book is the ARRL handbook. Good luck with your new learning adventure.

These blocks are not something you would typically want. For example, you can't purchase one from Mini-Circuits. For PDN, they needed to work at very low frequencies. This makes the VNA much easier to damage. These are a stacked ceramic. Of course, their value will change with voltage but I have set the low cutoff far below what I needed and typically I would never use them above 5VDC. In the description, there was a link to a thread on attenuators. www.eevblog.com/forum/projects/20db-rf-attenuator-seeking-feedback-to-improve/msg2965430/#msg2965430

Those are just sections of semi ridged coax. Center conductor is solid. Magnet wire was wrapped around the shield and plugged into the board.

@@joesmith-je3tq Thank you! Im learning a lot!

Not physically but I had looked at their blog.

Sorry I can''t be of much help. You can try asking in the email group groups.io . They are cheap enough that you could just buy one and try it.

@@joesmith-je3tq Hi Joe & thanks for your prompt reply ... I have now posted in the groups.io nanovna-users group and hope they may know about this. And, yes, I realize these nanoVNAs are not costly - it is more the time that may go into trying to figure out why something does not appear to work. I think your software looks really great - and I indeed appreciate the opportunity to be able to use it - but not being a programmer I know that I could spend hours upon hours trying to find out what could be amiss if something does not work. And, admittedly, I'd rather discover electronics, circuitry and components (using your software) in this time ... Cheers, Jesper

@@irpheus Most of the common problems people run into are a result of them not reading the documentation rather than the product. That said, we are looking at one now that seems to have known hardware problem with the USB supply voltage. Most of the problems I have personally had with the products has been poor firmware. A few people have written me about using the H4 with my software. I never had any luck getting that combination to work but it's possible the newer firmware has improved.

@@joesmith-je3tq Hi Joe ... just saw your message. Hmmm ... having thought about things I reckon it might be feasible to mention what I would actually like to measure (noticing in your videos that you are interested in digital circuitries and your demonstration of how an "unstable" amplifier did not work well with the cheaper VNAs): My VNA use is to measure PDN impedances on DACs and ADCs - WHILE - those components are powered up, yet - not - active (no clock or data signals). Thus, the intention is to also get an idea of the intrinsic "hidden" inductance/capacitance PSU pin characteristics of the DACs and ADCs in question - without the DAC/ADC actually sampling. Additionally to characterize components - including larger capacitors (up to several thousand microfarads). I am, however unsure if the square wave output signal of these cheaper VNAs will mess up such measurements? Might you have an idea about this? And, if you reckon it wouldn't work, might you then suggest a not too costly VNA that outputs sine waves (and it would just be a gift if it would also work with your software) and would work for these purposes? I would appreciate your feedback! ... Cheers, Jesper

The idea is to design the power distribution network for a flat impedance. What is being showing is an attempt to measure it with the NanoVNA.

You pick cap types with the ESR you are looking for.

For about 6 months now.

I assumed most people would have seen common mode transformer and one time or another and of course, I had shown one of the early ones in this video. I also had shown a few of the later ones on EEVBLOG. Even the core types were listed on the boxes of the two I made up. Hardly seems like much of a secret. There was a person on EEVBLOG that claimed to have a fair bit of experience in this area. I was hoping they would come up with an improved design that would be lower cost. More to your point, you are very much correct that without the tools and more importantly, the knowledge to use them, you are pretty much on a difficult path. That said, the original NanoVNA combined with the V2Plus4 should be good enough to get that job done.

@@joesmith-je3tq We are not as smart as you im afraid. You know how much small things about the implementation changes the performance. Like how much you twisted the wire etc. Thanks again!

@@heinrichhein2605 I wouldn't underestimate the viewers here. During the video, I mentioned this is a 50 ohm coaxial transformer. There's no twisting. However, you are very much correct that as we move up in frequency small details become more important. I expect viewers are are interested in learning which means digging in and getting your hands dirty. Of course there are certainly systems out there today that we use to make these measurements if that is what you are after. I mentioned some of them during the video.

@@joesmith-je3tq True as well, a lot of amazing people here, im maybe always curious if i see a box with electronics even if it is really mundane i just want to look inside you never know what you did not before. But yes, 50Ohm coax around a core is not exiting. But you always seem to have something to learn about even the simplest things. Thanks for putting such info out there for us!

@@heinrichhein2605 I agree that seeing coax wrapped around some cores isn't very exciting but I added a picture of one to the manual anyway for curious people like yourself to have a look at. You're not going to learn much from it. What is useful is having the S parameter data. From that you can calculate most of what you need to know. I wasn't going to publish the materials I selected as viewers pretty much have all they need given to them on a silver platter.

No reason really outside of the standards are male and I use a stainless F/F or coax to F connector. In this video, you see me using coax to M as well to connect to the breadboard.

Yes, I would not use a solid ground like I show. Better to use 4-wire at these lower values. Still, results were good enough for this demo and limitation was the VNA, not the test fixture. It may be difficult to break the ground loop at 6GHz with an active circuit. So it is going to depend what you are after. The low frequency limitation of what I show is once again, the VNA.